Arthroplasty Practice Research Articles

The role of surgeon volume on patient outcome in total knee arthroplasty: a systematic review of the literature

BackgroundA number of factors have been identified as influencing total knee arthroplasty outcomes, including patient factors such as gender and medical comorbidity, technical factors such as alignment of the prosthesis, and provider factors such as hospital and surgeon procedure volumes. Recently, strategies aimed at optimizing provider factors have been proposed, including regionalization of total joint arthroplasty to higher volume centers, and adoption of volume standards. To contribute to the discussions concerning the optimization of provider factors and proposals to regionalize total knee arthroplasty practices, we undertook a systematic review to investigate the association between surgeon volume and primary total knee arthroplasty outcomes.MethodsWe performed a systematic review examining the association between surgeon volume and primary knee arthroplasty outcomes. To be included in the review, the study population had to include patients undergoing primary total knee arthroplasty. Studies had to report on the association between surgeon volume and primary total knee arthroplasty outcomes, including perioperative mortality and morbidity, patient-reported outcomes, or total knee arthroplasty implant survivorship. There were no restrictions placed on study design or language.ResultsStudies were variable in defining surgeon volume (‘low’: <3 to <52 total knee arthroplasty per year; ‘high’: >5 to >70 total knee arthroplasty per year). Mortality rate, survivorship and thromboembolic events were not found to be associated with surgeon volume. We found a significant association between low surgeon volume and higher rate of infection (0.26% - 2.8% higher), procedure time (165 min versus 135 min), longer length of stay (0.4 - 2.13 days longer), transfusion rate (13% versus 4%), and worse patient reported outcomes.ConclusionsFindings suggest a trend towards better outcomes for higher volume surgeons, but results must be interpreted with caution.

Global Orthopaedics

Technological advances have shrunk the orthopaedic world. Today, more than ever before, there is a need to consider orthopaedics as an international specialty, with research being accomplished in and reported from every part of the globe. Information about new scientific findings and advances in patient care now can readily reach nearly every country and region. Over the past few years, The Journal of Bone and Joint Surgery has received more than half of its manuscript submissions from outside North America, yet it had no international members of its editorial board. In addition, the percentage of reviewers from outside North America has been small. The Journal has now taken important initial steps to begin to remedy the lack of representatives of the global orthopaedic community on our editorial board. Six new members of the editorial board from outside North America have been added. This group of international deputy editors represents not only multiple regions but multiple subspecialties. Plans are in place to add three more international deputy editors each year in 2012 and 2013. Until recently, the majority of the scientific reports from outside North America emanated from Europe, Scandinavia, and Japan. A large number of randomized clinical trials now submitted to The Journal originate in countries with national health systems, enabling patient-tracking to be done more easily than in the United States. More recently, as the economies of countries such as China, South Korea, Brazil, and India have developed, there has been a parallel upward growth in the amount of medical research being accomplished and a marked increase in submissions of scientific reports from these regions to The Journal. We are fortunate that The Journal attracts high-quality submissions from all parts of the world. The Journal and our readers are benefitting from this uptick in research reports submitted to us from outside North America. A simple example relates to information gleaned from the total joint arthroplasty registries that have been established in many countries worldwide. Similar efforts have lagged in the United States, where total joint arthroplasty registries are just now in their early stages. The data from these total joint arthroplasty registries from multiple countries have led to improved patient care not only in the country of the registry but globally, including in arthroplasty practices in the United States. A recent supplement published in JBJS1 addressed several topics related to the establishment of an International Consortium of Orthopaedic Registries (ICOR). By establishing large multinational joint registries and obtaining longitudinal follow-up data, it is expected that small to moderate clinically important differences in patient outcomes between the various arthroplasty devices used can be detected in a way not possible today. An additional example of the benefit that we derive from international research reports is the work that is done on orthopaedic disorders that are found commonly in developing countries and much less often in developed countries, such as tuberculosis involving the musculoskeletal system. With immigration active throughout the world, orthopaedists in developed countries will see conditions that they have rarely seen previously and the recommendations for treatment that come out of developing countries will allow us to establish earlier diagnosis of these uncommon conditions and provide better patient care. In addition, trauma is omnipresent in all countries and has been identified as a major factor in health-care costs in both developed and developing countries. Research in the world of trauma can have an impact on patient care regardless of the region in which the trauma occurs. The mission statement of The Journal is “To provide and disseminate worldwide the highest quality information about the musculoskeletal system.” The continuing commitment of The Journal to publish high-quality articles from around the world is important in fulfilling this global mission.

Computer-assisted surgery simulations and directed practice of total knee arthroplasty: Educational benefits to the trainee

Orthopaedic residents typically learn to perform total knee arthroplasty (TKA) through an apprenticeship-type model, which is a necessarily slow process. Surgical skills courses, using artificial bones, have been shown to improve technical and cognitive skills significantly within a couple of days. The addition of computer-assisted surgery (CAS) simulations challenges the participants to consider the same task in a different context, promoting cognitive flexibility. We designed a hands-on educational intervention for junior residents with a conventional tibiofemoral TKA station, two different tibiofemoral CAS stations, and a CAS and conventional patellar resection station, including both qualitative and quantitative analyses. Qualitatively, structured interviews before and after the course were analyzed for recurring themes. Quantitatively, subjects were evaluated on their technical skills before and after the course, and on a multiple-choice knowledge test and error detection test after the course, in comparison to senior residents who performed only the testing. Four themes emerged: confidence, awareness, deepening knowledge and changed perspectives. The residents’ attitudes to CAS changed from negative before the course to neutral or positive afterwards. The junior resident group completed 23% of tasks in the pre-course skills test and 75% of tasks on the post-test (p < 0.01), compared to 45% of tasks completed by the senior resident group. High-impact educational interventions, promoting cognitive flexibility, would benefit trainees, attending surgeons, the healthcare system and patients.

What is the True Incidence of Dental Pathology in the Total Joint Arthroplasty Population?

One million total joint arthroplasties (TJAs) are performed annually in the United States. The incidence of oral disease has not been documented in this population. To understand the scope of disease, a descriptive longitudinal population-based study sought to define the true incidence of dental pathology in the TJA population. One hundred consecutive TJA patients from a dedicated arthroplasty practice were sent for dental clearance, including oral examination, cleaning, radiographs, and treatment of active decay. The incidence of pathology was documented. Of 10 patients, 23 (23%) were treated before being cleared for arthroplasty. Sixty-six procedures were performed—2.9 problems per patient. No patient developed TJA infection. Routine preoperative dental clearance revealed 23% incidence of pathology, and no patient developed TJA infection.

The Practice of Unicompartmental Knee Arthroplasty in the United Kingdom

To survey the current practice of unicompartmental knee arthroplasty (UKA) in the United Kingdom. Questionnaires were sent to all 341 local members of the British Association for Surgery of the Knee to inquire into their practice of UKA, including clinical indications, preoperative investigations, surgical approach, preferences in implant design, and the role of UKA in relation to high tibial osteotomy. 56% of respondents performed less than 16 UKAs per year, whereas 16.5% performed over 30 per year. 89.5% of the respondents used anteroposterior radiographs as their main investigation tool. Only 30% and 16.5% used posteroanterior 30 degrees flexion and varus/valgus stress radiographs, respectively, despite being better investigation tools. 57% considered arthroscopy, despite its invasive nature. The main contra-indications to UKA were anterior cruciate ligament deficiency with instability (95%), focal grade-III osteoarthritis in the contralateral compartment (87%), and osteoporosis with rheumatoid arthritis (80.5%), but only 59% of respondents considered an inability to passively correct a pre-existing varus or valgus deformity as a contra-indication. 51.5% of respondents preferred minimally invasive approach, 96% preferred cemented fixation, and over two thirds used the mobile bearing design. 72% of respondents expressed preference for total knee arthroplasty over UKA in localised lateral compartment osteoarthritis. Modern UKA has gained popularity in properly selected patients with localised medial compartment osteoarthritis, provided the knee is not anterior cruciate ligament deficient and any deformity is passively correctable.

Reply to Letter to the Editor: Do “Premium” Joint Implants Add Value?: Analysis of High Cost Joint Implants in a Community Registry

I read with interest the letter from Mr. McClure and Dr. Heeckt in reference to our recent article [1], and acknowledge the limitations of joint registry data when evaluating the value to be gained from newer (and inevitably) more expensive designs. Indeed, some of the concerns raised by Mr. McClure and Dr. Heeckt are inherent in any implant/explant registry such as the HEJR and may serve as either limitations or strengths, depending on one’s point of view. Selection bias was not controlled, and certainly activity level or rehabilitation potential is not captured in most implant/explant registry databases. However, age as a crude proxy for activity level was adjusted for as a confounder in the Cox regression analysis, as noted in the article. The fact that different surgeons select different implants for different patients for different reasons is exactly what makes analysis of these types of data so valuable; it mirrors the practice of orthopaedic surgery in a community setting. Similarly, the critique of surgeon volume as another potential contributor to device longevity, although accurate, may not reflect the current reality of arthroplasty practice in North America. Mr. McClure and Dr. Heeckt point out that a “full economic cost analysis” would be more appropriate to assess the value of newer devices, and we fully agree. However, as we pointed out in the limitations section of the Discussion, an implant/explant registry database cannot provide that information. We disagree that the “premium implants” discussed in our article are implanted with instruments or techniques that are substantially different from the standard implants referenced, or that the former is somehow “fast, safe, simple, and flexible” compared with the latter. All innovation is not progress in the right direction, as the field of arthroplasty surgery has shown time and again. If Mr. McClure and Dr. Heeckt actually believe that “innovation inexorably adds to cost”, then I fear for innovation in our present global healthcare setting. Finally, we previously reported (and referenced in our article) our 94% capture rate for followup, similar to the Scandinavian registries. Although this is a limitation for all such registries, this presumably would affect the premium and standard device recipients in a similar distribution, as we noted in the Discussion. We thank Mr. McClure and Dr. Heeckt for their thoughtful review of our paper, agree with their conclusion that “assessment of value in healthcare is a very complex task”, and hope that the article has added to the debate in some small way.

Hip resurfacing: expectations and limitations

Hip resurfacing: expectations and limitations

Multimodal Pain Management after Total Hip and Knee Arthroplasty at the Ranawat Orthopaedic Center

Improvements in pain management techniques in the last decade have had a major impact on the practice of total hip and knee arthroplasty (THA and TKA). Although there are a number of treatment options for postoperative pain, a gold standard has not been established. However, there appears to be a shift towards multimodal approaches using regional anesthesia to minimize narcotic consumption and to avoid narcotic-related side effects. Over the last 10 years, we have used intravenous patient-controlled analgesia (PCA), femoral nerve block (FNB), and continuous epidural infusions for 24 and 48 hours with and without FNB. Unfortunately, all of these techniques had shortcomings, not the least of which was suboptimal pain control and unwanted side effects. Our practice has currently evolved to using a multimodal protocol that emphasizes local periarticular injections while minimizing the use of parenteral narcotics. Multimodal protocols after THA and TKA have been a substantial advance; they provide better pain control and patient satisfaction, lower overall narcotic consumption, reduce hospital stay, and improve function while minimizing complications. Although no pain protocol is ideal, it is clear that patients should have optimum pain control after TKA and THA for enhanced satisfaction and function. Level V, expert opinion. See the Guidelines for Authors for a complete description of levels of evidence.

Unicompartmental Knee Arthroplasty with Use of Novel Patient-Specific Resurfacing Implants and Personalized Jigs

This paper describes the surgical technique with a patient-specific resurfacing unicompartmental knee arthroplasty. The patient-specific implant is currently designed on the basis of data from preoperative computed tomography. The implant is provided with a set of patient-specific, disposable cutting jigs. Biomechanical and anatomic axes are factored into jigs from a scan obtained through the hip, knee, and ankle, effectively achieving pre-navigation of the cut planes without the need for a navigation system. The surgical technique is reduced to five simple, reproducible steps. After removing the articular cartilage, the knee is balanced to determine the correct amount of tibial resection; this is followed by femoral preparation, verification of balancing and tibial preparation, and trial and cementing of the implant. The introduction of personalized three-dimensional image-derived resurfacing implants, as well as personalized single-use instrumentation, has the potential to change the common surgical practice of unicompartmental knee arthroplasty. Patient-specific resurfacing implants enable a femoral bone-preserving approach and enhance cortical bone support on the tibia, overcoming critical design limitations of commercial off-the-shelf implants. Patient-specific resurfacing implants can restore normal anatomy, the position of the joint line, and normal joint function, with the potential to result in more normal knee kinematics.

Thromboembolism Prophylaxis Efficacy in a Practice-Based Registry

Thromboembolism prophylaxis is both an important and vexing consideration for the arthroplasty surgeon. The American College of Chest Physicians (ACCP) guidelines led many surgeons to alter their previous strategy. Recently, the American Academy of Orthopaedic Surgeons (AAOS) work group published an alternate set of guidelines that incorporates assessment of risk. The AAHKS 2007 Rand Award Paper documented the efficacy of aspirin in the Medicare population (Bozic et al., AAHKS 2007). This is an observational cohort study examining the efficacy of thromboembolism prophylaxis in a dedicated arthroplasty practice.

Effects of Increased Surgical Volume on Total Knee Arthroplasty Complications

The relationship between surgical volume and patient outcomes has been evaluated using large databases comparing numerous surgeons and hospitals based on relative surgical volume. In contrast, this study determined the affect of increased surgical volume on the incidence of knee complications within a single surgeon's primary total knee arthroplasty (TKA) practice.

Current Etiologies and Modes of Failure in Total Knee Arthroplasty Revision

Although total knee arthroplasty is a very effective intervention and increasing in prevalence, failures do occur. We studied patients presenting for total knee arthroplasty revision to determine any modifiable causes of failure, both short and long term, and where future efforts should be directed to reduce the incidence of failure. A multicenter prospective observational cohort study of 318 consecutive patients, with minimum 1 year follow-up, undergoing total knee arthroplasty revision was performed. Associations between modes of failure were also assessed. The mean time from primary procedure to total knee arthroplasty revision was 7.9 years. Many patients (64.4%) had more than one cause of failure. Thirty-one percent of patients were early (< 2 years) failures at a mean of 11 months. These had a higher prevalence of infection, perioperative factors and comorbidities. Late failures occurred at a mean of 119.2 months. Other major causes of failure included instability (28.9%), wear (24.5%) and component loosening suggesting the importance of modifications in technique, implants and other areas. Application of these findings will ultimately reduce revision numbers through continued refinement of total knee arthroplasty practice and through further specific investigation of these modes of failure. Therapeutic study, level II-2 (prospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Thermal analysis of the cruciate ligaments of the human knee

Cruciate ligaments of the knee joint are important structures very often affected by the degenerative process in case of osteoarthritis. One of the most controversial issues in knee arthroplasty practice nowadays is the role of the posterior cruciate ligament. With foregoing studies authors have demonstrated the feasibility of DSC in the investigation of the musculoskeletal system. With current study authors established the thermal behaviour of healthy cruciate ligaments and detected the alterations in case of osteoarthritis. By establishing the DSC scans of the normal ligaments authors demonstrated clear differences between the posterior and anterior ligament. In addition alterations between normal and arthritic samples could be detected both in terms of changes in total enthalpy and heat capacity. Calorimetric findings have been verified by histological examinations as well.

Hip arthroplasty, changing trends in a national tertiary referral centre.

Despite changes in techniques and management, little has been published comparing hip replacement surgery over a three-decade time span. To document change in the practice of hip arthroplasty in a large elective orthopaedic centre. A retrospective analysis of 100 patients in 1979 and in 1999 comparing demographics, surgical approaches, blood loss, transfusion requirements, morbidity and length of stay. In 1999, males predominated, spinal anaesthesia had largely superceded general anaesthesia, the anterolateral approach had replaced the trans-trochanteric approach, osteoarthritis remained the main aetiology and the Charnley prosthesis remained the implant of choice. Average blood loss was higher in 1999 compared to 1979 (1,378 vs 1,225 ml) but all patients in 1979 were transfused with an average of 2.8 units while in 1999 one-third of patients were transfused with an average of 1.6 units (p<0.0001). Length of stay had fallen from 30.5 days in 1979 to 16.2 days in 1999 (p<0.0001). Thromboembolic complications fell from 13% to 2% (p=0.0083). The incidence of deep venous thrombosis (DVT), pulmonary embolus (PE) and length of hospital stay has fallen. Blood loss had changed little but fewer patients receive blood transfusion.

How Outcome Studies Have Changed Total Hip Arthroplasty Practices in Sweden

The Swedish Hip Registry has defined the epidemiology of total hip replacement in Sweden. Most hip implants are fully cemented. Serious complications and rates of revision associated with total hip replacement have declined significantly despite an increasing number of patients at risk. During the past 5 years only 9% to 10% of hip replacement procedures are revision procedures. Aseptic loosening with or without osteolysis is the major problem and constitutes 73% of the revisions, but the incidence has decreased four times during the past 15 years to less than 3% at 10 years. Even septic complications can be prevented effectively. Demographics are important because male gender and young age increase the risk for revision because of aseptic loosening. Young female patients with rheumatoid arthritis and male patients with a previous hip fracture have five times higher revision rates than elderly patients. The quality of the surgical technique is the most important factor for reducing the risk for revision because of aseptic loosening, but choice of implant is also important. The variations among hospitals in type of surgical technique used is big enough to cause a 100% difference in revision rate for aseptic loosening. Total hip replacement practice in Sweden has improved based on information from this Registry about individualized patient risks, implant safety, and the efficacy of improving surgical and cementing techniques.